When a compact disc is playing, the angular speed of the turntable is adjusted s

Question

When a compact disc is playing, the angular speed of the turntable is adjusted so that the laser beam, which reads the digital information encoded in the surface of the disc, maintains a constant tangential speed. the laser begins tracking at the inside of the disc and spirals outward as the disc plays, while the angular speed of the disc varies between 490 rpm and 190 rpm. A certain CD plays for 72.0 minutes and has a playing area of the outer diameter 12.1 cm (which is also essentially the outside diameter). What is the diameter of the inside of the playing area of this CD? What is the angular acceleration of the CD while it is playing, assuming it to be consant?

Explanation / Answer

1.diameter of the inside of the playing area of this CD

D of playing area = 2r*190/490 =4.69 cm

2.  angular acceleration of the CD

alpha = delta omega/t = (2pi*(190-490)/60)/(72*60) = -7272205E^-3 rad/s^2.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.